Soot-blowing provision for fluid-heating apparatus



Oct. 22, 1929. BELL 1,732,429

500T BLOWING PROVISION FOR FLUID HEATING APPARATUS [q 1N VENTOR A TTOR/VE V Oct. 22, 1929. J. E. BELL SOO'I BLOWING PROVISION FOR FLUID HEATING APPARATUS Filed April 26, 1925 4 Sheets-Sheet 2 11v VENTUR B y Z fiiLZQ t/wm A 'ITORNE r Oct. 22, 1929. E, BELL 1,732,429

5001' BLOWING PROVISION FOR FLUID HEATING APPARATUS Filed April 26, 1923 4 Sheets-Sheet 5 o o o o o IIIIIIIIIIIII 4 Sheets-Sheet J. E. BELL Filed April 26, 1925 500'! BLOWING PROVISION FOR FLUID HEATING APPARATUS Illl'llrl Oct. 22, 1929.

Patented Del. 22, 1929 UNITED STATES PATENT OFFICE JOHN E. BELL, OF BROOKLYN. NEW YORK, ASSIGNOR TO FOSTER WHEELER CORPORA- TION, OF NEW YORK, N. Y., A CORPORATION 01 NEW YORK SOOT-BLOWING PROVISION FOR FLUID-HEATING APPARATUS Application filed April 26, 1923. Serial No. 634,712.

My present invention relates particularly to fluid heating apparatus of the type in which the fluid to be heated is circulated through channels in a metallic structure which is exposed to the interior of a heating chamber, and absorbs heat from said chamber wholly or largely by radiation, as distinguished from contact with, and conduction from the heating gases in the chamber.

The main object of my invention is to provide apparatus of the type referred to with improved soot blowing provisions, i. e., provisions for blowing soot and ashes or other furnacedust fromthe heat absorbing faces of apparatus of the type described. My invention is of special utility for use in the socalled radiant heat superheaters incorporated in the Walls of boiler furnace combustion chambers,and a second object of the invention is to provide for the regulation of superheating efi'ect obtained in such a superheater, by regulating the amount of soot, ashes or other turnace dust deposited on the heat absorbing surface of the superheater.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to, and forming a part of this specification. For

a better understanding of the invention, how- Fig. 19;

ever, its advantages, and specific objects attained with its use, reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described preferred embodiments of my invention.

Of the drawings:

Fig. 1 is an elevation in section of a portion of the wall of a combustion chamber in which a radiant heat superheater is incorporated;

Fig. 2 is an elevation of a portion of the inner wall of the combustion chamber shown in Fig. 1, with parts broken away and in section;

Fig. 3 is a partial section onthe line 3-3 of Fig. 2;

F g. 4 is a longitudinal section of a portion of one oi? the superheater elements of Figs. 1, 2 and 3;

Fig. 5 is a section on the line 5-5 of Fig. 4;

Fig. 6 is a section taken similarly to Fig. 4 showing a modified construction;

Fig. 7 is a section taken similarly to Fig. 4 illustrating another modification;

.Fig. 8 isan elevation taken similarly to Fig. 2 of a portion of a modified construction;

Fig. 9 isasection on the line 9-9 of Fig.8;

Fig. 10 is a section on the broken line 1010 of Fig. 8;

Fig. 11 is an elevation taken similarly to Fig. 2 of another modification;

Fig. 12 is a section on the line 1212 of Fig. 11.;

Fig. 13 is asection on the line 13-13 of Fig. 11;

Fig. 14 is a section taken similarly to Fig. i

4 of a portion of a modified construction;

Fig. 15 is a section on the line 15-15 of Fig. 14;

Fig. 16 is an elevation of another modification;

Fig. 17 is a section on the line 1717 of Fig. 16;

Fig. 18 is a View taken similarly to Fig. 17 illustrating a modification;

Fig. 19 is an elevation of another modification;

Fig. 20 is a section on the line 20-20 of Fig. 21 is a diagrammatic sectional elevation of a boiler furnace; 1

Fig. 22 is an elevation of a portion of the inner side wall of the combustion chamber of Fig. 21;

Fig. 23 is a section on the line 2323 of Fig. 22; and

Fig. 24 is a section on the line 2424 of Fig. 22.

In the embodiment of my invention shown in Figs. 1 to 5, A represents a boiler furnace combustion chamber wall incorporating a radiant heat superheater provided with one form of soot blowing provisions constructed in accordance with the present invention. The superheater shown comprises a plurality of elements B which are shown as vertically disposed, though they may be horizontal. Each element B is connected at its ends by horizontal pipes C to inlet and outlet headers D and DA. Each superheater element -B is formed of hollow sections connected at their ends by threaded nipples or sleeves E. The joints between the section ends thus connected are advantageously sealed by welding the sections together as indicated at F. The sections ar formed of cast metal, such as ordinary cast steel or more refractory steel alloys. Each of the elements B has a plane -heat absorbing face exposed to the-interior of the combustion chamber, and has side faces perendicular to its inner face, and in the assembled superheater, the inner faces of the various elements unite to form a substantially smooth or plane heat absorbing surface.

The superheated elements B are formed at their rear sides with bosses B for connecting the elements to suitable supports. These supports, as shown in Figs. 1 to 3, comprise angle bars 9 arranged arallel to, and one immediately behind eac element B. These angle bars are formed with holes to receive bolts 9 tapped into the bosses B To accommodate relative longitudinal expansion of each element B and the corresponding support 9, each element may be rigidly clamped adjacent its center, to its support 9, by the corresponding bolt g, while the holes in that element 9 through which the other bolts 9 pass may be longitudinally slotted. The angle bars 9 may, or may not be connected to, and form a part of a structural metal framework Gr back of the superheater, which assists in carrying the weight of the masonry furnace wall above the superheater. If so connected, the angle bars 9 form means for carrying the weight of the superheater element, and when not so connected, the superheater elements may be suspended from their upper ends, or may rest at their lower ends against a suitable abutment or support. In any event, the pipes C provide the flexibility needed to accommodate the thermal expansion and contraction of the elements B relative to the external columns, or metallic framework by which the headersD and DA are supported.

In the operation of a superheater, as shown in Figs. 1 to 4, soot, ashes and other furnace dust deposit on the heat absorbing face of the superheater, and such deposits diminish the heat absorption capacity of the superheater.

To remove such deposits, I have provided the superheater with novel provisions for sweeping the deposited dust, ashes or other furnace dust fromthe heat absorbing face of the superheater, with jets of a suitable cleaning fluid as superheated steam. These provisions com prise a plurality of nozzles mounted in the superheater structure. The nozzles are protected against overheating from the combustion chamber by arranging the nozzles to contact with adjacent portions of the superheater ducted through the adjacent portions of the superheater to the steam circulating through the channels therein. Passages are provided in the superheater structure for supplying the nozzles with a cleaning fluid.

The soot blowing provisions shown in Figs. 1 to 5, comprise nozzles each of which is formed by the closed end of a tubular member H which traverses the steam thoroughfare B of the corresponding superheater element B, and is threaded into the latter at opposite sides of said thoroughfare. To seal the joints between each member H and the superheater element into which it is threaded, the parts are advantageously welded together as indicated at H. The nozzle end of each member H is enlarged to form a head H which abuts against the heat absorbing face of the superheater element proper, and in which are formed a series of angularly displaced radial discharge orifices H, through which a suitable cleaning fluid, supplied under proper pressure to the interior of each member II, is discharged in jets parallel to, and closely adjacent to the heat absorbing surface of the superheater. The inner end of each member H may advantageously be polygonal in outline to facilitate the application of a wrench for screwing the member into and out of place. To provide sufiieient flow space for the steam flowing past the members H, the superheater element thoroughfares B may advantageously be enlarged, as indicated at B adjacent each member H. I

The various members H are so disposed that the jets discharged by them will sweep the entire heat absorbing face of the superheater. As shown in Figs. 1 to 4, the members H are arranged in transverse rows spaced a couple of feet or so apart, a portion only of the various superheater elements B having members H mounted in them. Each transverse row of members H is provided with a common supply pipe I and branch supply pipes I connecting the individual members to the common supply pipe. Each pipe I is connected by an individual control valve I to a cleaning fluid supply main 1'. When, as in the construction shown in Figs. 1 to 5, the heating apparatus is a radiant steam superheater, the cleaning fluid supplied to the main I may well be superheated steam, though other cleaning fluids supplied under suitable pressure may be employed.

With the cleaning provisions described. the heat absorbing face of the superheater can be kept as free as may be desired of deposited soot, ashes or other furnace dust. The cleaning fluid may be supplied intermittently or constantly to the members H. When supplied intermittently, the sections of the superheater at different levels may be successively cleaned, each section being swept with the proper amount of cleaning fluid. While I contemplate supplying cleaning fluid to the nozzles intermittently in ordinary practice, it may sometimes be desirable lo supply cleaning fluid continuously and this is possibl as the cleaning fluid jets discharged over the heat absorbing surface do not materially affect the absorption of radiant heat by said surface. The independcut control of the amount of cleaning fluid supplied for cleaning ditl'erent sections of the superheater is advantageous, however, whether the cleaning fluid is supplied intermittently or continuously.

Since the heat absorption by a supcrhcater of the type described, diminishes rapidly as the accumulation of furnace dust on its heat absorbing surface increases, I may regulate the superhcating eil'ect obtained, by operating the soot blowing provisions in such fashion as to maintain a minimum average thickness of deposit when a high superheating effect is desired, and to maintain a deposit of greater average thickness when a lesser super-heating effect is desired. For instance, inthe normal. operation of a super heater boiler having a radiant heat superheater there is a tendency for the degrees of superheat to decrease as the rate at which steam is generated increases. When the rate at which steam is generated varies more or less gradually and uniformly during various periods in each day, as is the case in most large central power stations, I may thus obtain an approximately constant superheat by keeping the heat absorbing face of the entire aiperheater, or portions thereof, comparatively clean during the heavy boiler load periods, and allowing dust deposits to remain on said face or portions thereof, dur- I .ing periods in which the load is lighter. The soot blowing provisions may also be operated to permit dust deposits to accumulate and protect the superheater against overheating during very light and no load periods in which the superheater elements -might otherwise become overheated. The method of regulating the heat absorbing capacity of radiant heat apparatus by regulating the furnace dust accumulations on the heat absorbing face of the apparatus disclosed but not claimed herein, is disclosed and claimed in the divisional application Serial No. 4,181, filed January 23, 1925.

Many modifications of the soot blowing provisions shown in Figs. 1 to 5 may be made, and in Figs. 6 to 24: of the accompanying drawings I have illustrated several such modifications. In Fig. 6, I illustrate a modification in which the tubular nozzle members H of Fig. at are replaced, each by an open ended tubular body HA, extending across the thoroughfare in the superheater element in which it is mounted, and by a separate nozzle member HB which is screwed into a threaded socket formed in the end of the body member HA. The parts HA and HE thus unite to form a nozzle member generally similar to the nozzle member II first described, but the construction shown in Fig. 6, has the advantage that the nozzle part l llt which projects into the furnace chamber from the face of the super-heater, and is sulr ject to deterioration after extended periods of use, may readily be removed for cleaning, repairs or rephu-ement.

The constri'iction shown in Fig. 7 differs from that shown in Fig. 6 in substance, in that the tubular body part TIA. of Fig. (3 is replaced by an integral tubular portion II of the SlllJOI'llQtltlIlg element casting 13A. The thoroughfare through the portion II is enlarged and threaded at the outer side ot the supcrheater for connection to the piping I supplying the cleaning fluid, and at its opposite end the thoroughfare is enlarged and threaded to receive a nozzle part IIB like the nozzle part IIB of Fig. (i.

In the construction shown in Figs. 8, 9 and '10, the superheater elements BB are formed with lugs or projections B on their heat absorbing faces, and the thoroughfare B througl'i each superheater element BB is encircled by a passage B for the cleaning fluid. A portion of the passage I3 is within the lug B and communicates with discharge orifices 13 formed in the end of the lug B. As shown the orifices B are parallel to the length of the superheater element, and with this arrangement, each superheater element is provided with cleaning jet orifices. The cleaning fluid supply piping is tapped into the outer side of the element to communicate with the corresponding portions of the channels B.

-Figs. 11, 12 and 13, illustrate a construction analogous to that shown in Figs. 8, 9 and 10, .in that the cleaning nozzle orifices B are formed in the end of lugs B on the heat absorbing face of the superheater elements BC, but in this construction the fluid chamber Pf in each lug 13 does not extend around the thoroughfare B, but the lug B and chamber B are extended to one side of the body of the element BC, to permit the supply piping I tapped into one end of the chamber B, to be received in semi-cylindrical grooves 13 formed in the adjacent sides of adjacent sections BC.

In the construction shown in Figs. 14 and 15, the nipples F connecting adjacent sections of the superheatcr elements are elongated, and are surrounded byspecial nozzle sections HO which may be welded to the adjacent ends of the superheater element sections to seal the joints. Each section HC is formed with a boss or lug B, cleaning fluid channels 13, and discharge orifices B as in the construction shown in Figs. 8, 9 and 10.

In the construction shown'in Figs. 16 and 17, the cleaning fluid nozzle members III) are tubular elements, each closed at one end, except for the radial discharge orifices H Each member IID is axially movable in a channel formed in the superheaterstructure,

member HD is axially movable, comprises a semi-cylindrical channel in each of the adjacent sides of adjacent superheater elements BD. Each member ED is normally retracted, as by means of a spring H mounted in a cylinder I 12 secured to the outer side of the superheater. The cleaning fluid supply piping I is tapped into the outer ends of the cylinders I and when cleaning fluid is supplied, the pressure of the fluid acting against the piston enlargement II" of the member HD, forces the latter from its full line position into the dotted line position against the tension of the corresponding spring H WVith this arrangement the nozzle ends of the members HD are effectually protected against the furnace heat during periods in which they are not cooled by the discharge of the cleaning fluid through them.

Fig. 18 illustrates a modification of the apparatus shown in Figs. 16 and 17 in which a cylinder H replaces the cylinder member H and a rotary valve K is arranged to connect either end of the cylinder H to the cleaning fluid supply piping I, while connecting the other end of the chamber to an exhaust outlet connection K. l/Vith thearrangement shown in 18, the cleaning nozzle members HD may be advanced and retracted as in the construction shown in Figs. 16 and 17, but the movement in each direction is due to fluid under pressure acting on the piston H In the construction shown in Figs. 19 and 20, the cleaning fluid is fluid taken directly from the thoroughfares B of the superheater elements B. For this purpose threaded passages are formed in the superheater elements between the thoroughfare B and the heat absorbing faces of the elements, and nozzle members HE are secured in these passages. Each nozzle member I-IE may be like the nozzle members HB of Fig. 6, except that each is provided at-its inner end with a valve seat H against which a valve member L normally bears toclose communication between the interior of the nozzle and the corresponding steam thoroughfare B. As shown the valve member L comprises 'a threaded spindle portion mounted in an internally threaded valve barrel member L threaded into a corresponding orifice in the outer wall of the thoroughfare B. Each barrel L maybe provided at its outer end with a suitable stuffing box L Advantageously the valve spindle L has an operating member L secured to its outer end and comprising a lever arm L carrying a counter-weight L which constantly tends to rotate the valve in the closing direction and thus keep it tight against its heat H While my present invention was primarily devised for, and is especially useful in connection with steam superheaters, it is not limited to such use, but on the contrary is adapted for use with apparatus for heating any sort of fluid circulating through channels in a metallic structure having one face exposed to a heating chamber filled with dust carrying gases. For instance, my invention may well be employed with heating apparatus forming a part of the water heating surface o l' a boiler. Thus, as shown in Fig. 21, elements shown as similar to the, elements BB of Figs. 8, 9, and 10. are mounted in a boiler furnace combustion chamber wall, and are connected at their upper ends into the upper headers M of an inclined water tube boiler, while the lower headers M of the boiler may be connected by piping to the lower ends of the elements BB through a header M and pipes M In this construction the elements BB form a part of the water heating surface of the boiler. In lieu of the elements BB, any of the other forms of elements and soot blowing provisions hereinbefore described may be en'iployed in the construction shown in Fig. 21.

My improved soot blowing provisions are not limited to use in connection with superheater or other elements in the form of hollow castings as employed in the constructions heretofore described, but may be employed with superheaters and analogous apparatus of the well known type in which ordinary steel pipes are surrounded by hollow blocks of cast iron or cast steel to increase the heat absorbing surface and to protect the wrought steel pipes from direct exposure to the furnace temperature and to the furnace gases. In heating apparatus of this type, I may replace some of the ordinary cast iron or cast steel blocks surrounding the bare wrought metal tubes by special blocks or hollow bodies in which soot blowing provisions are incorporated. One instance of this type of construction is illustrated in Figs. 22, 23, and 24: in which B represents the wrought steel tubes, 'and B represents the usual cast steel blocks surrounding these tubes to increase their heat absorbing capacity and to protect the tubes. At suitable points in the apparatus, the plain blocks or casing elements B are replaced by special casing elements IIC which might be exactly similar to the parts HC of Figs. 14 and 15. As shown, however. the elements HG differ from the parts I-IC in that the nozzle lug portion H of each element HC is formed with an annular known to me, it will be apparent to those.

skilled in the art that many changes may be made in the form of the apparatus disclosed without departing from the spirit of my in vention as set forth in the appended claims,

and that certain features of my invention may sometimes be used with advantage without a corresponding use of other features.

- Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. Fluid heating apparatus comprising a plurality of parallel metallic conduit elements assembled to form a structure having a smooth face exposed to the interior of a furnace chamber, channels opening through said face and means communicating with said channels through which a cleaning fluid may be discharged in jets sweeping over said face.

2. Fluid heating apparatus comprising metallic parts assembled to form a wall like structure having a smooth face exposed to the interior of a furnace chamber and a thoroughfare for the fluid to be heated, and provisions for discharging cleaning fluid jets over said face, said provisions including nozzle parts incorporated in said structure and cooled by contact therewith.

3. Fluid heating apparatus comprising a metallic structure having a face adapted to be exposed .to the interior of a furnace chamber and a t oroughfare for fluid to which heat is conducted from said face and having a passage transverse to said face, and a nozzle in contact with said structure and adapted to receive fluid through said passage and discharge it over said face to clean the latter. v

4. Fluid heating apparatus comprising metallic parts assembled into a structure having a smooth heat absorbing face adapted to be exposed to the interior of a furnace chamber and having a thoroughfare for the fluid to be heated to which heat is conducted by said structure from said faceyand nozzles incorporated in said structure and projecting from said face and having orifices adapted to discharge jets of cleaningfluid over said face, said structure being formed with channels through which cleaning fluid is supplied to said nozzle orifices.

5. Fluid heating apparatus comprising a hollow metallic element having a face posi tioned to receive radiant heat and soot blowmg provlsions including a nozzle formlng an integral portion of said element projectingfrom said face and arranged to discharge a cleaning fluid along said face.

6. Fluid heating apparatus comprising metallic parts assembled to form a structure having a smooth face exposed to the interior of a furnace chamber and having a thoroughfare for the fluid to be heated and provisions mounted in said apparatus for discharging jets of cleaning fluid sweeping over said face from points distributed over said face and means for separately regulating the jet discharge over different portions of said face whereby the different portions may be cleaned at different times and to different degrees.

7. Fluid heating apparatus comprising metallic parts assembled to form a structure having a smooth face exposed to the interior of afurna'ce chamber and having a thoroughfare for the fluid to be heated and nozzles mounted in said structure at points distributed over said face and means for separately regulating the supply of cleaning fluid to different groups of said jets whereby different portions of said face may be cleaned at different times and to different degrees.

8. A steam superheater comprising metallic parts assembled to form a structure having a smooth face exposed to the interior of a furnace chamber and passages back of said face for the steam to be superheated, and soot blowing provisions associated with said structure and operable to regulate the accumulation of furnace dust on said face and thereby control the amount of superheat imparted to the steam passing through said channels.

9. A steam superheater comprising metallic parts assembled to form a structure having a smooth face exposed to the interior of a furnace chamber with passages back of said space for the steam to be superheated and soot blowing provisions associated with said structure and comprising a plurality of nozzles for discharging cleaning fluid jets along said face, said nozzles being distributed relative to said face so that the jets'discharged by the different nozzles clean different portions of said face, and cleaning fluid supply connections to the different nozzles whereby different sections of said face may be cleaned at different times.

10. In a boiler, a steam superheater consisting of a plurality of parallel conduit elements, each of said elements having asmooth inner face exposed to the radiant heat of the combustion chamber, the inner faces of said elements being arranged in the same plane, and soot blowing means incorporated in said inner faces at spaced points for discharging jets of cleaning fluid along said faces to re move dust deposits thereon.

11. A steam boiler furnace comprising a combustion chamber in which fuel is adapted to be burned at high temperatures, a series of parallel fluid conduits incorporated in a ma sonry portion of the furnace and exposed to heat radiation from the combustion chamber an ash receiving space adjacentthe lower end of said conduits, the radiant heat absorbing face of said conduits being subject to furnace'dust accumulations thereon, and'mcans, 'for regulating the rate of heat absor tion of 10 said face comprising cleaning fluid distribut- 7 ing means at the upper end of said conduits. 12. A steam boiler furnace comprising a combustion chamber in which fuel is adapted to be burned at high temperatures, a plurality of parallel fluid conduits forming a metallic wall portion exposed to heat radiation from the combustion chamber and on which furnace dust tends to accumulate, an ash receiving space adjacent the lower end of said conduits, and means for regulating the rate of heat absorption of said wall portion comprising means for removing the furnace dust from difl'erent parts of said wall portion at different times.

13. A steam boiler furnace comprising a combustion chamber in which fuel is adapted to be burned at high temperatures, a plurality of parallel fluid conduits forming a metallic wall portion exposed to heat radiation from the'combustion chamber and on which furnace dust tends to accumulate, an ash receiving space adjacent the lower end of said conduits, and means for regulating the rate of heat absorption of said wall portion comprising cleaning fluid distributing means for removing the dust from said wall portion andmllowing it to pass by gravity to said ash receiving space. Signed at city of New York, in the county of New York and State of New York this 19th 7 day of April, A. D. 1923.

1 JOHN E. BELL. 

